Nouveaux complexes monométalliques actifs en imagerie : Intérêt potentiel dans le cadre d’une approche nanoparticules pour une imagerie bimodale

International audienc

New Bioconjugates derived from the PCTA[12] macrocyclic platform

International audienc

Highly luminescent Tb(III) macrocyclic complex based on a DO3A hosting unit and an appended carboxylated N,C-pyrazolylpyridine antenna

International audienc

Synthesis of 18F–19F isotope exchange-ready zwitterionic aryltrifluoroborate bioconjugates

LDM TEPInternational audienc

Fluoride Trapping and Release with Boranes: Application to 18F-Radiochemistry

LDM TEPInternational audienc

Fluoride Trapping and Release with Boranes: Application to 18F-Radiochemistry

LDM TEPInternational audienc

Cationic Boranes and Trifluoroborates: attractive alternate introduction of 18F

LDM TEPInternational audienc

Cationic boranes as attractive tools for radiochemistry with fluorine-18

LDM TEPInternational audienc

[ 18 F]-Fluoride capture and release: azeotropic drying free nucleophilic aromatic radiofluorination assisted by a phosphonium borane

LDM TEPInternational audienc

Synthesis, characterization and in vitro evaluation of new oxorhenium- and oxotechnetium-CCK4 derivatives as molecular imaging agents for CCK2-receptor targeting.

International audienceThe goal of this study is to design new (99m)Tc-radiolabelled shortened CCK derivatives that might be suitable for the molecular imaging of cholecystokinin-2 receptors (CCK2-R), these receptors being over-expressed in a number of neuroendocrine tumors such as medullary thyroid cancer and small-cell lung cancer. For this purpose, we designed several modified CCK4 analogs bearing an ON(2)S tetradentate chelating agent at the N-terminus, the CCK4 sequence representing the minimal peptide sequence that presents nanomolar affinity and activity towards the CCK2-R. Four peptide conjugates of general formula (Trt)SN(2)OPh-(X)(n)-CCK4 (X=beta-alanine or 6-aminohexanoic acid spacers; n=0, 2, 4) and their oxorhenium peptide conjugates have been synthesized and characterized. In vitro evaluation of these compounds showed a close relationship between the nature and the length of the spacer and the corresponding binding affinity values. The most promising oxorhenium complex 5-Re exhibited potent CCK2-receptor agonist properties in promoting the production of inositol phosphate in COS-7 cells (EC(50)=5.17nM). Preliminary (99m)Tc-radiolabelling studies with peptide conjugates 3 or 5 led exclusively to the corresponding (99m)TcO-complexes 3-Tc and 5-Tc, which exhibited high resistance towards an excess of cysteine and satisfactory stabilities in human serum. To conclude, the promising in vitro characteristics of compounds 5-Re, 5-Tc illustrate the feasibility to develop stable radiolabelled shortened CCK4 derivatives with a nanomolar CCK2-R affinity